The present disclosure relates to a sheet correcting device corrects the curl of the sheet and an image forming apparatus including this.
A sheet of paper on which an image has been formed by an electro-photographic image forming apparatus is often curled (has a curling habit). The sheet curls along a conveyance (discharge) direction (referred to also as a ‘regular curl’ hereinafter) by being nipped by a fixing unit (fixing nip part), a discharge roller pair and the like. The sheet also curls along a width direction orthogonal to the conveyance direction (referred to also as a ‘side curl’ hereinafter) by being heated by the fixing unit in a condition in which environmental humidity is high for example (see FIG. 15). If the sheet being side-curled is stacked on a sheet discharge tray, there is a case when a succeeding sheet discharged to the sheet discharge tray pushes out the sheet stacked on the sheet discharge tray. Then, a sheet stacking failure occurs on the sheet discharge tray.
Then, technologies for suppressing the sheet stacking failure are being proposed. For instance, an electro-photographic apparatus includes a plurality of pressing parts at widthwise both sides of a sheet. The plurality of pressing parts presses widthwise both sides of a side-curled sheet against a sheet receiving surface of a sheet discharge tray. This arrangement makes it possible to prevent the sheet stacking failure.
However, because each of the pressing parts of the electro-photographic apparatus described above merely presses the already side-curled sheet against the sheet discharge tray, it is unable to fully correct the side curl of the sheet. That is, each of the pressing parts of the electro-photographic apparatus described above is unable to remove a cause (side curl of sheet) of the stacking failure. Still further, because each of the pressing parts of the electro-photographic apparatus described above forcibly presses the sheet against the sheet discharge tray, there is a problem that a scratch is left on an image formed on the sheet.